1. Field of the Invention
The present invention relates to devices used in the manufacture of shoes, and more particularly to shoe sole molds used in the manufacture of unitary shoe soles.
2. Prior Art
Shoe manufacturing has advanced through many stages, from the craftsman sewing leather together and stitching a leather sole to an upper, to the current practice of injection molding a unitary sole and cementing the pre-molded sole to a completed upper.
Changes in styling have necessitated variations in the shape and characteristics of the pre-molded sole. Some of this styling has included embellishments and various ornamentation on the side, as well as the bottoms, of the soles. The ornamentation has included the use of welting on the pre-molded sole to give it the appearance of leather stitched to the top periphery of the sole. In a pre-molded sole this welting has to be placed in the mold and secured there prior to filling of the mold cavity with the sole material. The bottom edges of the welting must be secure to the finished sole. It is difficult to seat the welt material in the mold cavity so that it fits properly and will be secure with the finished sole. Other ornamentation may include a leather or synthetic material insert adapted around the outside surface of the heel. The use of another decorative insert can be almost impossible to accomplish in combination with the welting on the sole, without the use of a more complicated mold arrangement, such as utilizing one mold member for holding the welting, and the other mold member holding the leather heel insert. This may lead to problems of alignment and of matching up the pieces in the mold members as well as having the mold members themselves mate properly, because both mold halves would have to be moved for the machine operator to have access thereto for inserting the ornaments.
Some patents which show sole molding include British Pat. No. 1,520,044; French Pat. No. 2,383,770 and U.S. Pat. No. 3,813,201.
It is an object of the present invention to provide a mold arrangement which permits the use of several ornaments with the molding of a unitary sole.
It is a further object of the present invention to provide a mold arrangement which facilitates the use of several ornamental features therewith, in a simple, efficient and effective manner, in an ordinary molding machine where only one mold half is moved for access thereto by the machine operator.